The need to reduce system cost, provide greater functionality, and enable higher levels of precision and efficiency are continually pushing semiconductors towards higher levels of integration. Many applications would benefit from the integration of one or more vertical power devices with logic, analog, and mixed-signal circuitry including sensors within a single die. The benefits include reduced product cost due to integration, enabling of higher functionality, improved component matching, and improved thermal matching due to the shared substrate.
Vertical power devices such as superjunction MOSFETs, IGBTs, and diodes are used in numerous power applications, one example being MOSFETs in switch-mode power supplies. Many of these applications require external circuitry to allow the control circuitry (e.g., a microprocessor) to interface with these power devices in an optimal way. For example, many applications require a separate gate driver IC to interface between the control circuitry and the power device in order to provide the power device with the gate voltages it requires to switch optimally. To reduce system cost, provide greater functionality, and enable greater precision and efficiency, it would be advantageous to be able to embed various types of control circuitry within the power device die. The present disclosure provides a method of integrating and embedding many types of surface devices (e.g., NMOS, PMOS, etc.) within a vertical device die.